Updates to Instant Navs devtools functionality (#91005)
Updates the Instant Navs devtools functionality to use a panel and show
you two options for capturing the SSR shell or the prefetch for a Client
navigation.
Replaces current functionality where clicking Instant Navs changed the
devtools indicator to a blue pending state awaiting the user's next
navigation.
https://github.com/user-attachments/assets/de5c5a40-e836-4719-9517-6d5c6b0aef2c
